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Troubleshooting BB-View for Beaglebone Black and QT Embedded (uncalibrated touchscreen)

  • Hi there,

    I'm currently developing software for a beaglebone black (BB) through QT.

    I'm successfully cross-compiling to the BB but I'm having issues with the touchscreen module ((BB-View 4.3 inch LCD)).

    I have tslib compiled on the BB and can run ts_calibrate and ts_test. They both function correctly and the etc/pointercal file is updated correctly.

    I compiled qt on the BB with the -qt-mouse-tslib option in the configuration. However, if I attempt to run the program with -qws, the touchscreen does not seem to be calibrated. The pointer jitters when the touchscreen is used and the axes seem to be inversed.

    I've also attempted to use the QWSCalibratedMouseHandler class, using the example provided:


    It runs through the calibration but the same issues persist: the pointer jitters and the axes are inversed.

    Any advice would be greatly appreciated.

  • Replying to myself as I've found the solution. If other people face the same issue they may find this to be the fix.

    under /etc/environment I had the line: QWS_MOUSE_PROTO="Tslib:/dev/input/event1"

    However, this didn't seem to work. I'm not entirely sure why, I'll probably look into it.

    If, however, I use: export QWS_MOUSE_PROTO="Tslib:/dev/input/event1" , and then run the application, it functions correctly.